Clinical trials of BIONs/spl trade/ for therapeutic electrical stimulation

BIONs/spl trade/ are individually addressable, single channel electrical stimulators that can be injected into one or more muscles through a 12-gauge hypodermic needle. They receive power and command signals from an externally worn RF transmission coil. Two clinical trials are underway to determine their safety and efficacy for strengthening atrophic muscles associated with stroke (7 patients accrued; 6 implanted) and chronic osteoarthritis of the knee (5 patients accrued; 3 implanted). In both studies, BIONs/spl trade/ have proven easy for the clinician to implant and for the patients to use. Thresholds for recruitment of muscle contractions have remained stable and no adverse effects have been reported. Patients generally like the stimulation and most have elected to continue stimulation after the prescribed study period. Stimulation at low frequencies for a total of about 1 hour/day has produced demonstrable reversals of muscle atrophy as measured by imaging. In patients with radiological subluxation of the shoulder, the subluxation has been reduced. Preliminary indications suggest also that chronic pain has been reduced and locomotor function has improved in patients with knee osteoarthritis.